1. Technical Field
The present invention relates to a liquid crystal device and an electronic apparatus.
2. Related Art
A liquid crystal device capable of providing a display to be viewed by using the external light in a bright place and an internal light source such as a backlight in a dark place has been proposed. That is, the liquid crystal device uses both reflection type of display and transmission type of display. Hereinafter, the liquid crystal device is referred to as a “transflective liquid crystal device” in the present specification.
FIG. 10A is a plan view of a sub-pixel of a liquid crystal device of the related art. FIG. 10B is a cross-sectional view of a liquid crystal device taken along line XB-XB line in FIG. 10A. As shown in FIG. 10A, within each sub-pixel which is a unit of image display, the transflective liquid crystal device comprises a reflective region R on which a reflective film is formed and a transmissive region T on which a reflective film is not formed.
Recently, such transflective liquid crystal devices have been required to output color light according to the development of portable apparatuses, etc. For this reason, as shown in FIG. 10B, a colorant layer 22 of a color filter of red R, green G and blue B is formed. In the case of this kind of transflective liquid crystal device, after the light incident on a panel in a reflective mode is transmitted through the colorant layer 22 of the color filter, it is reflected from a reflective film 21 and then transmitted through the colorant layer 22 again. Meanwhile, in a transmitting mode, illumination light incident from illuminating means such as a backlight is transmitted through the colorant layer 22.
As described above, in the transflective liquid crystal device, color display is obtained by allowing the incident light to be transmitted through the colorant layer 22 twice in a reflective mode and once in a transmissive mode. For this reason, when the colorant layer 22 of a light color is provided in order to appropriately realize the color in a reflective mode, it is difficult to obtain good chromogenic display in a transmissive mode. Meanwhile, when the colorant layer 22 of a dark color is provided in order to appropriately realize the desired color in a transmissive mode, the display in a reflective mode is excessively dark.
Therefore, a liquid crystal display device having the non-colored region NC in which the colorant region 22 does not exist in a portion of the reflective region R has been proposed (for example, see JP-A-2003-195296). In this case, a portion of light is transmitted through the non-colored region NC in a reflective mode. Therefore, the light transmitted through the colorant layer 22 in the reflective mode becomes the light consisting of the non-colored light transmitted through the non-colored region NC overlapping the colored light transmitting the colored region CL. Meanwhile, all the light transmitted from the transmissive region T in the transmissive mode is transmitted through the colored region CL so as to become colored light. The shade difference between colors can be decreased in the reflective mode and the transmissive mode. Therefore, if the colorant layer 22 is optimized, display of good color quality and good visibility can be obtained in both the reflective mode and the transmissive mode.
However, the liquid crystal device as described above has the following problems.
First, as shown in FIG. 10B, there is a problem that a step difference occurs between the colored region CL in which the colorant layer 22 exists and the non-colored region NC in which the colorant layer 22 does not exist. Since the colorant layer 22 is made of resin, it is necessary to make the thickness of the colorant layer 22 to be in the range of 0.5 to 2.0 μm to improve color purity. Therefore, even when an overcoat film (planarization film) 24 is formed over the colorant layer 22, a large step difference G of as much as 0.2 to 0.7 μm remains on the surface thereof. Therefore, the deviation of the cell thickness in the liquid crystal device causes deterioration of the electro-optical characteristics. If the thickness of the colorant layer 22 is large to improve the color purity, the difference in the cell thickness between the colored region CL and the non-colored region NC is also large, causing problems such as a domain generation in the liquid crystal device in an STN mode.
A light shielding part 20 neighboring a sub-pixel is formed of a black resin material in which silver, carbon, etc. are dispersed. The black resin is poor in terms of exposure sensitivity so that it cannot be formed having narrow width. Therefore, the light shielding part 20 becomes wider than deemed necessary to reduce the aperture ratio, causing a problem in that a displayed image becomes dark.